Houseplant · Nephrolepidaceae
Kimberly Queen Fern
Nephrolepis obliterata
Give it bright indirect light and steady moisture, and its upright sword-shaped fronds stay full, green, and tidy all year.
Bright indirect
Every 3–7 days
61–75°F · 16–24°C
USDA 9–11
Overview
The Kimberly Queen fern is an Australian sword fern whose fronds tell you at a glance which fern it is. Each long, sword-shaped blade climbs stiff and upright from the crown, cut into rows of narrow green leaflets that hold their line instead of drooping over the pot. That firm, self-supporting posture sets it apart from the loose, arching Boston fern.
A well-grown plant sends up a dense fountain of these blades to about 2 to 3 feet (60 to 90 cm) tall, spreading nearly as wide as the fronds fan outward from the center. It fills in at a moderate pace and, being perennial, layers on more blades season after season until the crown reads as a full, rounded tuft of green.
The look holds only when its needs are met: light it can stand in but not scorch under, soil kept evenly damp, and air that is not too dry. Given those, the leaflets stay a deep, even green from base to tip. Let the rootball go dry and that even color breaks first at the tips, where thin brown tips creep in along the edges.
Care
The short version: bright indirect light, soil kept evenly moist but never soggy, and humidity on the higher side keep the fronds deep green and firm. Feed it monthly through the growing season and cut spent fronds at the base to keep the tuft clean.
Light
Give it bright indirect light, the soft light near an east window or a few feet back from a brighter one. It stands partial shade and a little gentle sun, but harsh midday glare bleaches and scorches the green leaflets.
Water
Keep the rootball evenly moist, watering once the top inch or so of soil feels dry, which usually falls every 3 to 7 days. Wet the whole rootball each time yet never leave it waterlogged, and ease off a little through winter.
Soil
Set it in a rich, humusy potting mix that drains freely, a dark, peat-based blend with organic matter worked through it. It leans slightly acidic, happiest around a pH of 5.5 to 6.5.
Temperature
Ordinary room warmth suits it, ideally between 61°F and 75°F (16°C to 24°C). Cold drafts and the hot breath of air vents both dry and stress the fronds, dulling their color.
Humidity
This fern wants high humidity, around 40% to 70%, more than most homes carry in winter. A pebble tray, a cluster of plants, or a humidifier keeps the fine leaflet tips from crisping to brown.
Feeding
Feed it monthly from spring to early fall with a balanced liquid houseplant fertilizer at half strength, which fuels the flush of new green blades. Hold off in winter while growth slows, and flush the pot now and then so salts do not build up.
Pruning
No hard pruning is needed. Just cut away dead, browned, or yellowed fronds at the base as they appear, which keeps the tuft clean and green and opens the crown for fresh blades.
Repotting
Move it into a slightly larger pot every 1 to 2 years, or sooner once roots circle the rootball or push out the drainage holes. Spring repotting is also the moment to split a crowded, dense clump.
Size & spacing
Indoors it stands about 2 to 3 feet (60 to 90 cm) tall with a spread of 2 to 4 feet (60 to 120 cm) as the fronds fan out. Leave room on every side so those upright blades can arch outward at the tips without pressing a wall or a neighbor.
Troubleshooting
Almost every problem this fern has is written on its fronds, in a change of color or texture, and most of it comes from water or air that has run too dry. Read the leaflets early and the fix is small. Match what you see below, then adjust before the whole crown turns.
Whole fronds paling to yellow as the plant sinks
Whole fronds drain from green to a sickly yellow and the once-upright blades sag, the mark of soggy soil and root rot underneath from overwatering. Too little light drains the color the same way. Let the surface dry before the next watering, see that the pot drains, and set the plant where the light is brighter.
Fix:
- Let the top of the soil dry slightly and ensure the pot drains freely
- Move to a brighter spot with bright indirect light
- Remove rotted roots and repot into fresh, well-draining mix if rot is present
Fine webbing, sticky sheen, or raised bumps across the fronds
Hot, dry air brings spider mites, whose fine silken webbing threads the leaflets while their feeding pales the green into a faint, dusty stippling. A sticky sheen or small raised brown and white bumps mean scale or mealybugs are clinging to the fronds instead. Rinse the foliage, lift the humidity, and set the plant apart while you wipe the pests from every leaflet.
Fix:
- Rinse the foliage and raise humidity to discourage mites
- Wipe scale and mealybugs off or dab with insecticidal soap
- Isolate the plant until the infestation is controlled
Brown, papery crisping at the frond tips and margins
The green gives way to a dry, papery brown right at the tips and along the leaflet margins, the first tissue to fail when the air is too dry or the rootball parched between waterings. A crust of fertilizer salts in the soil singes those edges the same way. Raise the humidity, water more evenly, and rinse the pot through now and then to carry the salts off.
Fix:
- Raise humidity with a pebble tray, grouping plants, or a humidifier
- Keep the rootball evenly moist and water more consistently
- Flush the pot occasionally to leach out accumulated fertilizer salts
- Trim off badly browned fronds at the base
Toxicity
For anyone with pets, the fronds hold good news: this is a true fern with nothing toxic in it. The ASPCA lists Nephrolepis ferns as non-toxic to cats and dogs, and the same holds for other household animals. The most a curious pet risks from a mouthful of the tough, fibrous leaflets is a brief, mild stomach upset.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
A cat is safe beside this fern. Should one bite through a leathery, fibrous frond, no poison follows, and even a big stringy mouthful brings at most a little drooling or a hairball-style upset that passes on its own.
Dogs None
No toxin sits in the tissue, so a dog can crunch a frond unharmed. A large helping of the tough, stringy foliage may loosen the stomach for a while, then settle without treatment.
Horses Safe
This true fern holds nothing in its green blades that would poison a horse, so a graze in passing is nothing to worry over.
Rabbits Safe
A rabbit can nibble the fine-cut leaflets safely. They are not a staple food, so keep it to the odd taste alongside the usual hay and greens.
Livestock Safe
Goats, sheep, and cattle take no poisoning from the fronds of this fern, whether from a potted plant indoors or one grown outdoors.
Birds Safe
Pet birds can perch on the arching fronds and pick at the leaflets without risk, an easy match for a home with parrots or finches.
People Safe
The fern is safe to handle and grow around adults and children. It is not grown for eating, so there is no edible part to seek out, only harmless green fronds to enjoy up close.
Although non-toxic, the fibrous fronds can cause mild, temporary stomach upset if a pet eats a large amount.
Varieties
This fern comes as a single named selection rather than a spread of cultivars, so there is one form to picture: the stiff, upright, sword-fronded plant described here.
'Kimberly Queen'
This clonal selection of Nephrolepis obliterata, the form on nearly every garden center bench, carries stiff, upright sword-shaped fronds that stand tall and hold together, shedding far less litter than the loose, arching Boston fern.
How to propagate
Making more Kimberly Queen ferns is easy and free, since the dense clump divides cleanly and also creeps outward on its own by runners.
DivisionEasy
Spring to early summer, ideally at repotting · 4 to 8 weeks
The plant multiplies by division, done in spring or early summer when you repot. Pull the dense rootball apart into sections that each keep a knot of roots and several fronds, pot them separately, and they knit in over 4 to 8 weeks. Sword ferns also throw out runners that creep outward and root, widening the clump on their own.
Myths
Kimberly Queen fern is poisonous to cats and dogs.
The ASPCA lists Nephrolepis ferns as non-toxic to both cats and dogs. No poison hides in those green fronds, and the most a pet meets after a large bite is a brief, harmless stomach upset.
Like every fern, it must sit in deep shade.
Sword ferns in this group take more light than the Boston fern does. A bright morning window or dappled sun keeps the fronds a full, even green, so long as the harsh midday glare that scorches them is kept off.